Recovery of Rare Earth Elements from Geothermal Fluids through Bacterial Cell Surface Adsorption

Abstract

We summarized the FY17 and part of FY18 results of the analysis of the effect of several parameters (e.g., total dissolved solids, specific competing metals, pH, and temperature) on REE recovery from geothermal brine in a manuscript that was submitted to Environmental Science & Technology.

In this manuscript, we investigate biosorption as a potential means of recovering REEs from geothermal fluids, a low-grade but abundant REE source. We have previously engineered E. coli to express lanthanide binding tags (LBTs) on the cell surface and the resulting strain showed an increase in both REE adsorption capacity and selectivity. Here we examined how REE adsorption by the engineered E. coli is affected by various geochemical factors relevant to geothermal fluids, including total dissolved solids (TDS), temperature, pH, and the presence of competing trace metals.